I and a sysadmin have done some more research into this and it seems that the problem is not with Evolution but with the IMAP server. We are using dovecot and it doesn't appear to be storing the labels in the mails.
To confirm I tried setting labels with Thunderbird too, with the same problem happening. Thanks Andrew -- Mail labels removed https://bugs.launchpad.net/bugs/314325 You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is a bug assignee. -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs